The first recorded use of the term Welsh rabbit was in 1725, according to the Oxford English Dictionary or before 1637 according to the US food processing conglomerate General Mills [dubious – discuss], but the origin of the term is uncertain. One theory is that 'Welsh rabbit' is an ironic name coined in the days when the Welsh were notoriously poor: only better-off people could afford butcher's meat, and while in England rabbit was the poor man's meat, in Wales the poor man's meat was cheese. Another theory is that the name was an intentional slur on the Welsh, since the dish contains no meat and so was considered inferior. Another theory is that because the word Welsh was at the time used by the English to describe anything inferior or anything foreign, the name alludes to the dish's Continental European origin.
Yet another theory as to the name 'Welsh rabbit' is put forth by the sales promotion department of General Mills in its Betty Crocker cookbook. According to the cookbook, Welsh peasants were not allowed to eat the rabbit caught in hunts on the estates of nobles[dubious – discuss], so they used melted cheese as a substitute[dubious – discuss]. The cookbook goes on to say that Ben Jonson[dubious – discuss] and Charles Dickens ate Welsh rabbit at Ye Olde Cheshire Cheese[dubious – discuss], a London pub, despite the fact that Ben Jonson died almost a century before the term Welsh Rabbit was first recorded in the UK.
It is also possible that the dish was attributed to Wales because the Welsh were considered particularly fond of cheese, as evidenced by Andrew Boorde in his Fyrst Boke of the Introduction of Knowledge (1542), when he wrote "I am a Welshman, I do love cause boby, good roasted cheese." In Boorde's account, "cause boby" is the Welsh caws pobi, meaning "roasted cheese". It is the earliest known reference to cheese being eaten cooked in the British Isles but whether it implies a recipe like Welsh rabbit is a matter of speculation.
The term Welsh rarebit was evidently a later corruption of Welsh rabbit, being first recorded in 1785 by Francis Grose, according to the Oxford English Dictionary. The entry in Merriam-Webster's Dictionary of English Usage is "Welsh rabbit, Welsh rarebit" and states: "When Francis Grose defined Welsh rabbit in A Classical Dictionary of the Vulgar Tongue in 1785, he mistakenly indicated that rabbit was a corruption of rarebit. It is not certain that this erroneous idea originated with Grose...."
According to the American satirist Ambrose Bierce, the continued use of rarebit was an attempt to rationalize the absence of rabbit, writing in his 1911 Devil's Dictionary: "RAREBIT n. A Welsh rabbit, in the speech of the humorless, who point out that it is not a rabbit. To whom it may be solemnly explained that the comestible known as toad-in-a-hole is really not a toad, and that riz-de-veau à la financière is not the smile of a calf prepared after the recipe of a she banker."
In his 1926 edition of the Dictionary of Modern English Usage, the grammarian H. W. Fowler states a forthright view: "Welsh Rabbit is amusing and right. Welsh Rarebit is stupid and wrong."
The word rarebit has no other use than in Welsh rabbit and, regardless of its evidently erroneous origin, "rarebit" alone has come to be used in place of the original name, and would be an example of an "eggcorn" if it weren't folk etymology.
In the 17th and 18th centuries, it was common in England to use the verb 'Welsh' to imply thievery or dishonesty – to 'Welsh' on a deal – or the adjective 'Welsh' to mean inferior quality or an outright counterfeit. In an age where practically everyone knew how to snare a rabbit for the pot, a Welshman was considered to be so lazy and inept that snaring a rabbit for the pot was beyond him. Cheese and bread had to do instead.